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The Enzyme Linked Immunosorbant Assay (ELISA) test of potato leaves collected from different areas within three (3) selected divisions in Khyber Pakhtunkhwa, Pakistan was carried out in 2016. The region-wise results showed the over all incidence of potato virus Y (PVY) to be highest in all the three divisions on potato crop followed by the incidence of potato leaf roll virus (PLRV). The PVYand PLRV incidence in Malakand divisionwas noted by 62.7 and 44.6 %, respectively. In Peshawar division the incidence of PVY was 55.4% and that of the PLRV was 40.7% and the incidence of PVY and PLRV was 50.7 and 37.3%, respectively in Hazara. The field-wise results of Malakand region showed the highest incidence of PVY and PLRV in Kalam was found by 70 and 50%) followed by Miandam (62 and 46 %) and the lowest incidence was recorded in Malamjaba (56 and 38%). In Peshawar the highest incidence of PVY and PLRV wasnotedon potato crop in Warmarh (66 and 46%) followed by Regi (52 and 32%) and the lowest was noted in Pul Dheri Mehra (48 and 44%). In the Hazara potato crop in Kaghan had 62 and 54% PVY and PLRV incidence followed by Bagnotar (48 and 36%) and the lowest incidence was noted in Kalanderabad (42 and 22%), respectively.Results obtained by this study indicating that both PVY and PLRV are major viruses of potato crop in selected potato growing areas of KPK province which could pose serious threat to the potato crop, development of resistance cultivar against vector insect could be recommended. [ABSTRACT FROM AUTHOR]

The most preferred method for the detection of foot-and-mouth disease (FMD) viral antigen and identification of viral serotype is the enzyme-linked immunosorbent assay (ELISA). Diagnostic tests with high sensitivity are necessary both to distinguish infected vaccinated animals and execute disease control programs for the identification of the carrier animals. The current strategies for the detection of FMD virus are mainly based on the capture antibody (sandwich) ELISA test. The usage of laying pullets as an animal bioreactor for the production of specific egg yolk antibodies (IgY) has increased in recent years due to its high yield, affinity, low price, and quick production turnover. The present study aimed to produce a concentrated and purified IgY polyclonal antibody to design a capture antibody ELISA kit against the FMD virus (FMDV) serotype A. At first, laying hens were immunized with inactivated FMDV serotype virus, and then, on days 14, 21, and 28 following vaccination, the eggs and sera were collected. Afterward, the IgY polyclonal antibodies were extracted and purified from the chicken egg yolk using a polyethylene glycol 6000–ethanol precipitation procedure. Extracts were filtered, purified by ion exchange chromatography, and dialyzed. The purified IgY concentration, estimated by Bradford assay, confirmed its presence by SDS-PAGE and Western blot and also its specific immune reaction by Ouchterlony double immunodiffusion and Dot blot tests . Moreover, for achieving the optimum concentration of antigen/antibody (sera) in sandwich ELISA, a checkerboard titration test was set up based on indirect ELISA results. Eventually, 119 previously confirmed samples (including 80 positive and 39 negative) by both real-time polymerase chain reaction (quantitative PCR, qPCR) and a commercial ELISA kit were used for evaluation of the sensitivity and accuracy of our developed Capture antibody ELISA kit. In this manner, the sensitivity and specificity of our designed kit were 100% and 98%, respectively. Accordingly, the present developed capture ELISA kit based on IgY had high sensitivity and specificity for FMD virus detection and it could be used in the future for both commercial detecting and serotyping applications. [ABSTRACT FROM AUTHOR]

Background: The coronavirus disease 2019 (COVID-19) was first reported in December 2019 in Wuhan, Hubei Province of China. As long as the 27th of December 2021, approximately 280 million people have been infected with coronavirus, resulting in more than 5,418,421 deaths worldwide. Since the beginning of the COVID-19 pandemic, different methods were introduced for diagnosing coronavirus-infected patients and evaluating the immune response, following the vaccination.Objective: The current study aimed to compare the level of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) specific IgG in a group of patients who recovered from COVID-19, measured by three different enzyme-linked immunosorbent assay (ELISA) kits.Methods: This cross-sectional study was conducted on sera from patients who recovered from a real-time reverse transcriptase-polymerase chain reaction (RT-PCR)-confirmed COVID-19 in Birjand, South Khorasan, Iran. SARS-CoV-2 anti-nucleocapsid (N) and spike (S) protein IgG levels were measured using commercial ELISA kits. Comparison between groups was made using one-way ANOVA and Tukey post hoc tests.Results: The mean titer of anti-N IgG was significantly higher for the PishtazTeb Diagnostics kit than the Ideal Tashkhis Atieh kit (p

Confirming detected SARS-CoV-2-specific antibodies is necessary to reveal immune response in COVID-19 convalescent subjects as well as to conduct population studies by screening for specific antibodies to assess rate of COVID-19 prevalence. With this purpose St. Petersburg Pasteur Institute was the first in Russia to develop the ELISA kit for the quantitative determination of human IgG to the SARS-CoV-2 nucleocapsid (N-CoV-2-IgG PS). Arbitrary units (AU/ml) were used to assess the level of antibodies. The data shown in AU/ml were recalculated later to the international units (BAU/ml) in accordance with established the First WHO International Standard for anti-SARS-CoV-2 human Immunoglobulin. Comparing the data of the N-CoV-2-IgG PS calibration curve with those of the First WHO International Standard for anti-SARS-CoV-2 human Immunoglobulin revealed a complete inter-assay association (r = 0.999, R2 = 0.997) allowing to find that 1BAU/ml = 5.97 AU/ml. The aim of the study was to characterize the SARS-CoV-2 protein N Human IgG Quantitative ELISA Kit (N-CoV-2-IgG PS), compare quantitative and qualitative data of ELISA kits, assess a correlation between the binding antibodies to SARS-CoV-2 N proteins and the neutralizing antibodies against SARS-CoV-2. The data of correlation analysis of the 83 COVID-19 convalescent blood plasma samples a significant relationship between the antibodies quantitative values and titers SARS-CoV-2-specific antibody (r = 0.8436, R2 = 0.7802) as well as a moderate relationship between antibody concentration and positivity index (r = 0.6648, R2 = 0.3307), assessed by Chaddock scale. Comparing concentration of N-protein binding antibodies with neutralizing antibody titers level uncovered data consistency obtained by quantitative and virus microneutralization assays (r = 0.7310, R2 = 0.6527) used in parallel to analyze 80 blood plasma samples obtained from COVID-19 patients and convalescents. AUC under the ROC curve comprised 0.701 (P 0.0001) evidencing about a satisfactory informative value for N-CoV-2-IgG PS compared with microneutralization assay. In addition, the efficacy of the N-CoV-2-IgG PS was 95%, while the positive and negative prognostic value was 97% and 87%, respectively. The data obtained confirmed a correlation between N-protein binding antibody level and neutralizing antibody titer. Checking inter-assay agreement evidenced about acceptance for informativeness and efficacy of using N-CoV-2-IgG PS, thereby confirming an opportunity to apply the Kit to screen for SARS-CoV-2 N protein-specific IgG antibody level and assess seroprevalence in diverse population cohorts.

Quality control is very important during the development of 3‐valent (16/18/58), 9‐valent (6/11/16/18/31/33/45/52/58), and 15‐valent human papillomavirus (HPV) vaccines (6/11/16/18/31/33/35/39/45/52/56/58/59/68). All 3‐valent, 9‐valent, and 15‐valent HPV vaccines contain the HPV16 antigen; therefore, a detection method that can specifically identify HPV16 in vaccines is urgently required. This study aimed to develop and characterize monoclonal antibodies to assemble a highly specific HPV16 detection kit. The HPV16 L1 pentameric protein developed as an immunogen was used to prepare monoclonal antibodies. From the pool of prepared monoclonal antibodies, we selected 4G12 and 5A6 to screen and evaluate their subtypes, specificity, neutralizing activity, serum competition, binding affinity, and gene sequencing. After these characterizations, an enzyme‐linked immunosorbent assay kit for these monoclonal antibodies was developed, and excellent quality was demonstrated in the assessment of linearity, repeatability, and specificity. The developed detection kit has great potential for wide use in clinical testing and quality control in vaccine production processes. [ABSTRACT FROM AUTHOR]

The enzyme-linked immunosorbent assay (ELISA), as a universal method for the determination of Microcystins, is of great significance for the rapid detection of Microcystins pollution. This study aimed to propose a simplified validation method for Microcystins ELISA kit by summarizing related documents and guidelines. After summarizing and clarifying from 20 validation parameters, 11 parameters were selected to simplify the validation of Microcystins ELISA kit. In addition, the acceptable range and validation details of each parameter were analyzed. The results indicated that the coefficient of determination of the Microcystin-LR standard curve was higher than 0.99. The concentration of quality control samples was within control limits. The accuracy of spiked and proficient samples was within 70%–130%. The variability of intra-assay, inter-assay, and reproducibility was less than 11, 15 and 21%, respectively. The LOD and LLOQ were 0.002 μg/L and 0.05 μg/L, respectively. When the concentration of Microcystins exceeded 5 μg/L, it was recommended to dilute the samples to the working range before detection. The specificity was estimated with seven Microcystin analogues and three amino acids, indicating that the cross-reactivity was less than 30%. These results revealed that the ELISA kit was satisfactory for detecting Microcystins in water. HIGHLIGHTS 20 validation parameters were summarized from related regulatory documents and studies.; 11 parameters were selected for Microcystins ELISA kit validation after the clarification and simplification of summarized parameters.; Acceptance range and validation details of selected parameters were investigated.; A simplified method for Microcystins ELISA kit validation was proposed.;

Determination of serum or plasma progesterone (P4) concentrations is important to recognize pregnant and non-pregnant ewes, and also to predict the number of carried lambs. The 2 most common methodologies for the detection of plasma P4 are radioimmunoassay (RIA) and enzyme immunoassay (EIA). RIA is very expensive, and not all laboratories are equipped to perform this test; EIA is commercially available for human use, but only a few companies produce species-specific kits, which are expensive. We verified for ovine plasma a less expensive and easily available ELISA kit (DiaMetra) designed to quantify P4 in humans. Pools of ovine and human plasma were used to compare repeatability, accuracy, sensitivity, and stability of P4 measured by the DiaMetra kit. Repeatability data were within 15%, and accuracy values were ~90% for both plasma matrices. Stability data showed a loss of <20% for freeze–thaw and <30% for 30-d storage. All parameters were acceptable under international guidelines for method validation. The human ELISA kit was used successfully to quantify plasma P4 in 26 ewes during pregnancy until delivery. P4 concentrations were also correlated with the number of carried lambs. [ABSTRACT FROM AUTHOR]

The human T-cell lymphotropic virus types 1 and 2 (HTLV 1/2) are well known causes of adult T cell leukemia lymphoma. Both viruses were established to be transmitted through various mode including sexual contact and blood transfusion. This study was aimed to determine the seroprevalence of HTLV-1/2 antibodies among blood donors in Public Health Laboratory. During the period of August 2019 to October 2019 a total of 394 blood samples were obtained from blood donors visiting the Blood bank of National Public Health Laboratory, both males and females were included. The blood samples were analyzed for the presence of anti - HTLV-1,2 by a commercially available enzyme-linked immune-sorbent assay following the instructions of the manufacturer. The study participants were included 361 (91.6%) males and 33 (8.4%) females. The result show that of the 394 blood donors, four (4) were found to be seropositive for HTLV-1 antibodies giving a prevalence of 1.02%. While all samples were negative for the HTLV-2 antibodies. Among HTLV-1 positive cases 3 were male (75%) while only one female (25%) was found to be seropositive for HTLV-1 antibodies. None of the married donors was found to be seropositive for HTLV-1. We conclude that the seroprevalence of HTLV 1/2 were matched to the internationally estimated prevalence among blood donors at Blood Bank of national health laboratory and the majority of the cases were male under 40 years old. Further studies should be done with inclusion of more samples and using more sensitive technique like Western blot or PCR.

Serosurveys provide the prevalence of infection and over time will reveal the trends. The present study was conducted to estimate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among healthcare workers (HCWs) and to analyse various characteristics (risk factors) associated with SARS CoV-2 infection. Eight government designated Corona virus disease -19 (COVID-19) hospitals were selected based on the hospital admission of patients with COVID-19 and the local epidemiological situation in the region. Multistage population proportion to size sampling was performed for the selection of HCWs. Serosurvey was conducted using the enzyme-linked immunosorbent assay–based IgG antibody test (COVID KAVACH). Bivariate and multiple logistic regression was performed to find out the factor/factors associated with the positive antibody test. Out of 3255 HCWs that participated in the study, data of 3253 were analysed. The seroprevalence was 19.7% (95% confidence interval: 18.5–21.3%). Factors associated were location, category of HCWs, male sex, previously tested positive by the molecular test, training on infection prevention and control, personal protective measures, handwashing technique, close contact with a patient confirmed with COVID-19, use of personal protective equipment and symptoms in the last 30 days. However, in multiple logistic regression, only location, category, previously tested positive by the molecular test and symptoms in the last 30 days were statistically significant. HCWs are vulnerable to SARS-CoV-2 infection. One in five HCWs had detectable antibodies. The presence of antibodies among HCWs may help in their placement and triage. HCWs may be advised to report early in case of any symptoms of COVID-19. Preventive measures may be targeted based on the location, with particular emphasis on ancillary workers and nurses. [ABSTRACT FROM AUTHOR]

A one-step incubation ELISA kit based on monoclonal antibody against dibutyl phthalate (DBP) was developed. After optimizing concentrations of coating antigen, antibody and composition of the assay buffer, an inhibition curve was plotted. The IC50 is 29.6 ng·mL-1, and the detection limit for DBP is 3.6 ng·mL-1. Compared with other ELISA methods, this ELISA kit had a simpler sample preparation, costed less time for detection and could detect more types of sample. The recoveries of DBP in water, beverage and liquor samples were range from 78% to 110.4%, the range of coefficient of variations is 7.7-15.3%. The cross reactivity was very low (&1%) except that for butyl benzyl phthalate (3.9%) and the di-isobutyl phthalate (12.5%). The detection results in liquor showed good correlation with those from GC-MS. All data above indicated that this kit could be used as the fast and high-throughput screening of DBP in water, beverage and liquor.

The administration of nitrofurans to livestock to treat or prevent animal diseases has been banned in the EU for the production of food of animal origin. The corresponding marker residues are tissue-related metabolites AMOZ, AHD, SEM, and AOZ. The MRPL (minimum required performance limit)/RPA (Reference point for action) was set at 1 µg kg−1 in the EU. Thus, all the laboratories involved in the control of nitrofuran metabolites must detect at least at this analytical limit of performance. The objectives of the work reported here were to evaluate the performance of ELISA kits from two different manufacturers (R-Biopharm, Germany; Europroxima, the Netherlands) for the individual screening of the four nitrofuran metabolites (AOZ, AMOZ; AHD; and SEM) in aquaculture products (fish, shrimps), and then to validate the kits according to the European Decision EC/2002/657 and to the European guideline for the validation of screening methods. The false positive rates were below 9 % for the kits from both manufacturers. The detection capabilities CCβ determined were all below the current RPA (1 µg/kg). However, regarding the updated RPA at 0.5 µg/kg that shall apply in 2022, the AMOZ and SEM kits from R-Biopharm and the SEM kit from Europroxima will not be able to reach it. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the use of a bovine procalcitonin (PCT) ELISA kit (Cusabio, China) for assessing PCT in bovine milk samples. Validation was performed by using 10 plasma and corresponding milk samples from mastitic cows. The limit of detection (LOD) was calculated. The coefficient of variation (CV%) of the readings of five plasma samples measured five times in the same plate (intra-assay) and the CV% of the same five samples read five times in three separate plates was evaluated. Parallelism was determined by serial twofold dilutions of five plasma and corresponding milk samples. Milk samples were analyzed with and without centrifugation. Regarding plasma PCT, the method presented an inter- and intra-CV < 23.7% and parallelism had very good recovery values. The ELISA kit studied can measure bovine plasma PCT concentrations. The kit antibodies fail in binding PCT in milk samples because all centrifuged milk samples showed a lower LOD than blank samples. Only three uncentrifuged milk samples showed measurable PCT concentrations. Due to these results, the commercial ELISA kit investigated could not be employed for the detection of PCT in milk samples.

Abstract Background HPV 18 is one of the most prevalent oncogenic types, only second to HPV 16, and included in the licensed vaccines on the market. In this study, we describe the production and characterization of a panel of monoclonal antibodies (mAb) to HPV18. Methods The immunocompetence of 1B1 and 4C2 mAbs for HPV L1 protein was evaluated by SDS-PAGE analysis, neutralization assays, affinity identification, and ELISA. The 1B1 and 4C2 genes were sequenced and analyzed. Finally, the detection kit with the two mAbs was assessed for linearity, repeatability and specificity. Results Both mAbs specifically recognized HPV18 L1 and virus-like particles (VLPs). These mAbs are conformation-neutralizing antibodies that have high affinity and type specificity. Based on these characteristics of these mAbs, we developed an ELISA kit for specifically detecting HPV 18 antigen. We showed that this kit displayed good linearity, repeatability and sensitivity for detecting HPV18 L1 pentamer and HPV18 VLP. Conclusions We characterized two monoclonal neutralizing antibodies for HPV L1 protein, and developed an ELISA kit for specifically detecting HPV 18 antigen. This newly developed kit can be used to monitor the potency of HPV vaccines throughout the entire production process as well as preliminary analysis of HPV18 infections.

Colistin is a polypeptide antibiotic mainly used in porcine and poultry to treat gastrointestinal infections. It has been included by the World Health Organisation (WHO) in the list of critically important human antibiotics of high priority for antimicrobial resistance since 2017. Therefore, it is necessary to develop specific and sensitive screening methods for this molecule. Screening for colistin with immunoassays is an interesting alternative to LC-MS/MS screening methods. The performance of three commercially available ELISA kits was evaluated in poultry and porcine muscles for the detection of colistin in regards to its European maximum residue limit (MRL) (150 µg/kg). The applicability of the three ELISA kits to the detection of colistin at or below the MRL in porcine and poultry muscles was demonstrated. The detection capabilities (CCβ) of two kits were or lower than or equal to the MRL (150 µg/kg). The lowest detection capability (30 µg/kg) was achieved with the third ELISA kit. The specificity of the three kits was very satisfactory (false positive rates 0%). The three kits are very specific for the detection of colistin (colistin A and B) and polymyxin B. [ABSTRACT FROM AUTHOR]

Gluten analysis is still affected by the lack of an efficient and universal extraction solvent for gliadin, i.e., the prolamine fraction of gluten which is the analytical target used to quantify gluten in food. In this investigation, the possibility of adopting pure choline chloride deep eutectic solvents (ChCl-DESs) as gliadin extraction media was tested. As prototypes of ChCl-DESs, ethaline and reline were chosen in view of their good dipolar and hydrogen bond donor (HBD) properties, as well as of their moderate enough viscosity. Their ability to act as effective solvents for gliadin and their inability to affect the subsequent gliadin detection by a frequently adopted and commercially available ELISA kit were first assessed. Ethaline and reline extraction performance was then tested by evaluating gliadin recoveries achieved on gluten-free food real samples before and after their spiking with controlled gliadin amounts. Higher recoveries were found by using these DESs in comparison with those gained by the usually adopted 60% ( v/ v) ethanol-water solvent. In fact, gluten recoveries ranging from 78 to 113%, with a RSD better than 13%, were achieved by using ethaline. Less good recoveries (from 67 to 132% with a RSD of 20%) were achieved with reline, even though they were however better than those found with 60% v/ v ethanol-water solvent. These results make the proposed media profitable solvents for gliadin extraction and its subsequent detection by a commonly used immunoassay kit, without any change of the usual detection procedure. [ABSTRACT FROM AUTHOR]

A total of 328 agricultural product samples highly suspected to be contaminated, from flour companies, feed companies, and livestock farms throughout China, were surveyed for deoxynivalenol (DON) contamination using a self-assembly enzyme-linked immunosorbent assay (ELISA) kit. An ELISA kit for DON was developed with a 4.9 ng mL−1 limit of detection (LOD) in working buffer and a 200 ng g−1 LOD in authentic samples. The DON contamination detection rate was 88.7%, concentrations ranged from 200.9 to 6480.6 ng g−1, and the highest DON contamination was found in distillers’ dried grains with solubles with an average of 3204.5 ng g−1. Wheat bran and wheat were found to be the most commonly contaminated samples, and the corn meal samples had the lowest average DON level. This ELISA kit is a powerful alternative method for the rapid, sensitive, specific, accurate, and high-throughput determination of DON and can meet the maximum requirement levels. This survey suggests that DON contamination in the Chinese market is serious, and the contamination risk deserves attention. Essential preventive measures should be implemented to ensure food safety and human health.

The purpose of this study was to develop a portable surface plasmon resonance (SPR) bioanalyzer for the sensitive detection of Escherichia coli O157:H7 in comparison with an enzyme-linked immunosorbent assay (ELISA). The experimental setup mainly consisted of an integrated biosensor and a homemade microfluidic cell with a three-way solenoid valve. In order to detect Escherichia coli O157:H7 using the SPR immunoassay, 3-mercaptopropionic acid (3-MPA) was chemisorbed onto a gold surface via covalent bond for the immobilization of biological species. 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) were used as crosslinker reagents to enable the reaction between 3-MPA and Escherichia coli O157:H7 antibodies by covalent -CO-NH- amide bonding. The experimental results were obtained from the Escherichia coli O157:H7 positive samples prepared by 10-, 20-, 40-, 80-, and 160-fold dilution respectively, which show that a good linear relationship with the correlation coefficient R of 0.982 existed between the response units from the portable SPR bioanalyzer and the concentration of Escherichia coli O157:H7 positive samples. Moreover, the theoretical detection limit of 1.87 × 10³ cfu/mL was calculated from the positive control samples. Compared with the Escherichia coli O157:H7 ELISA kit, the sensitivity of this portable SPR bioanalyzer is four orders of magnitude higher than the ELISA kit. The results demonstrate that the portable SPR bioanalyzer could provide an alternative method for the quantitative and sensitive determination of Escherichia coli O157:H7 in field. [ABSTRACT FROM AUTHOR]

Background: The association between maternal serum concentration of betamethasone given for fetal lung maturity and perinatal outcome has not been investigated. This may be due to an absence of a reliable method for measuring serum betamethasone concentrations. We aimed in the current study to assess the feasibility of a specific ELISA kit to measure the concentrations of betamethasone in maternal serum and to examine the trend of sequential measurements after a course of betamethasone for fetal lung maturity. Methods: Pregnant women at risk for preterm birth who received betamethasone between 24 and 34 weeks of gestation were prospectively included. Serum concentrations were determined before administering betamethasone (baseline), and 36 hours, 48 hours, 72 hours, and 5 to 7 days after the 1st dose. Betamethasone concentration in samples was determined using Corticosteroid ELISA kit. The Friedman test was used to test whether there were significant differences between the measurements. Results: Five singleton pregnancies were included. Using the ELISA kit, betamethasone concentration in maternal serum samples was obtained for all women. Among the five measurements performed, the concentration was highest at 36 hours after the 1st dose and close to baseline at the 5th measurement performed after 5 to 7 days (p < 0.05). Serum concentration varied at each time point between the five women but similar trend was observed. Conclusion: Betamethasone concentration is measurable in the serum of pregnant women with this ELISA kit. [ABSTRACT FROM AUTHOR]

Pregnancy diagnosis is an important tool for farm management. Ultrasonography is the main technique used for pregnancy diagnosis in ewes. As an alternative, radioimmunoassay (RIA) allows accurate and early detection of pregnancy-associated glycoproteins (PAGs) in sheep blood. However, radioactive-based techniques, as RIA, have been increasingly inadvisable due to environmental risk. Homology between ovine and bovine PAGs is high, and ELISA kits used for PAGs detection in cattle are safer than RIA. Thus, this study aimed to evaluate the feasibility of PAGs detection for pregnancy diagnosis in sheep serum samples using an ELISA kit produced for cattle. The sensitivity and specificity of the ELISA kit were 93.5% and 98.9%, respectively, whereas positive and negative predictive values were 99.0% and 93.1%, respectively, in comparison to ultrasonography diagnostic (control). PAGs reached consistently detectable concentrations in ovine serum around 33 days after mating. Accuracy of the ELISA test was 96.1% from 33 days of pregnancy until lambing. After parturition, PAGs were still detectable seven days post-lambing. However, from 21 days post-parturition, PAGs from the previous pregnancy were no longer detected in serum samples. In conclusion, the bovine ELISA kit can accurately detect pregnancy in sheep 33 days following mating, while PAGs levels from the previous gestation are no longer detected from 21 days post-partum. The evaluated ELISA test is a reliable tool for pregnancy diagnosis in sheep at random stages and as a complementary exam at early gestation. [ABSTRACT FROM AUTHOR]

Cystic hydatid disease (Hydatidosis) is the most serious tape-worm infection prevalent in the cattle and sheep raising area of the world. Hydatidosis in man (as an accidental host) caused by infection with the ova containing larval stage of Echinococcus spp. In the last decade different techniques have been employed for the serological diagnosis of hydatid disease, such as IHA, IFA, ELISA, CCLE (Counter Current Immuno Electrophoresis). The immunologic techniques used in this study were ELISA and CCIE. Since whole hydatid cyst fluid has been used as a source of antigen for serodiagnosis of hydatidosis. The result of examination of 30 patients that were surgically and pathologically proven to have hydatidosis was presented here. By appointing 1:100 serum liter ascut-off titer and using the crude antigen (concentration: 6 mµg/ml), sensitivity and specificity of the Elisa test were reported to be 93.3% and 96.6%,respectively. The Elisa was compared with CCLE in this study; it was found to have sensivity and specificity 90% and 100%,respectively. Finally, the result of our study showed that the ELISA kit designed in our study is easy to perform, not expensive, safe, and simple with good sensivity and specifity.

Aim A quantitative ELISA kit for the detection of human secreted CD306/LAIR-2 was developed using monoclonal and polyclonal antibodies which were raised against a highly purified recombinant human secreted CD306/LAIR-2. Methods Anti-human secreted CD306/LAIR-2 monoclonal and polyclonal antibodies were raised by immunizing mouse or rabbit with recombinant human secreted CD306/LAIR-2. The monoclonal antibody was purified by protein G affinity, whereas the polyclonal antibody was purified by protein A affinity. The best match pair of antibodies were found and used to develop a double antibody sandwich ELISA kit for the detection of human secreted CD306/LAIR-2 in human samples. Results A human secreted CD306/LAIR-2 ELISA kit was formulated with highly purified recombinant human secreted CD306/LAIR-2, highly specific monoclonal and polyclonal antibodies. This kit realized the quantitative measurement of recombinant human CD306/LAIR-2 and natural CD306/LAIR-2 in human serum samples. Conclusions The developed human secreted CD306/LAIR-2 ELISA kit is a reliable quantitation immunoassay kit. [ABSTRACT FROM AUTHOR]

Abstract: The analytical performance and evaluation of a kit-based ELISA for the determination of acrylamide in fried potato and corn chip samples are described. The sample homogenate is subjected to clean-up using SPE, followed by analyte derivatization and ELISA detection. Accuracy, precision and linearity of the ELISA procedure have been validated using spiked samples. Analytical recovery ranged from 91.8% to 96.0% with coefficients of variation below 15%. Good linearity over a wide range of dilution and minimal assay drift was observed within a microtiter plate. IC50 value of the calibration curve was 110ng/mL, with the limit of detection about 5ng/mL and dynamic range from 10 to 1000ng/mL. The high specificity of the ELISA was demonstrated by cross-reactivity study using 11 potential cross-reactants. A good correlation between the results obtained from the ELISA and GC–MS within the concentration range 120–1500μg/kg was found in the chip samples (r=0.992, n=120). The data demonstrate that the evaluated and validated ELISA has a potential utility in a quick, simple and reliable acrylamide screening analysis for the medium- and large-sized food companies, as well as for residue laboratories and the food industry dealing with improving the chemical safety of foods available to the consumer. [Copyright &y& Elsevier]

Abstract Only simple, point-of-care, assay formats of the Platellia Dengue NS1 Ag-ELISA would be suitable to identify Dengue virus in Aedes aegypti mosquitoes in dengue-endemic areas lacking sophisticated laboratory infrastructure and trained laboratory personnel.

Purpose: Analysis of anti-Müllerian hormone (AMH) is becoming of recognized importance in reproductive medicine, but assays are not standardized. We have evaluated the correlation between the new Gen II ELISA kit (Beckman-Coutler) and the older ELISA kits by Immunotech (IOT) and Diagnostic Systems Laboratories (DSL). Methods: A total of 56 archived serum samples from patients with subfertility or reproductive endocrine disorders were retrieved and assayed in duplicate using the three AMH ELISA kits . The samples covered a wide range of AMH concentrations (1.9 to 142.5 pmol/L). Results: We observed good correlations between the new (AMH Gen II) and old AMH assay kits by IOT and DSL (R = 0.971 and 0.930 respectively). The regression equations were AMH (Gen II) = 1.353 × AMH (IOT) + 0.051 and AMH (Gen II) = 1.223 × AMH (DSL) - 1.270 respectively. Conclusions: AMH concentrations using the Gen II kit are slightly higher than those from the IOT and DSL kits. Standardization of assay results worldwide is urgently required but this analysis facilitates the interpretation of values obtained historically and in future studies using any of the 3 assays available. Meanwhile, adapting clinical cut-offs from previously published work by direct conversion is not recommended. [ABSTRACT FROM AUTHOR]

Simple Summary: Mastitis is one of the major economic and animal welfare problems on dairy farms. The gold standard test for mastitis diagnosis is milk culture, but bacteria are not always isolated (only in 11–44% of milk samples from clinical cases of mastitis) and sometimes a positive culture can result from a contamination of the milk. Procalcitonin is a new biomarker which may lead to an early detection of inflammation due to bacterial infection. In humans, procalcitonin concentration has also been evaluated in milk in addition to plasma. The authors aimed to evaluate the possible application of a commercially available ELISA kit for bovine procalcitonin for the assessing of procalcitonin in bovine milk samples. Plasma and milk samples from cows with mastitis were collected to measure procalcitonin concentrations by using a bovine procalcitonin ELISA kit. Our results showed that the ELISA kit tested can be employed to assess bovine procalcitonin in plasma but not for analyzing milk samples. The aim was to evaluate the use of a bovine procalcitonin (PCT) ELISA kit (Cusabio, China) for assessing PCT in bovine milk samples. Validation was performed by using 10 plasma and corresponding milk samples from mastitic cows. The limit of detection (LOD) was calculated. The coefficient of variation (CV%) of the readings of five plasma samples measured five times in the same plate (intra-assay) and the CV% of the same five samples read five times in three separate plates was evaluated. Parallelism was determined by serial twofold dilutions of five plasma and corresponding milk samples. Milk samples were analyzed with and without centrifugation. Regarding plasma PCT, the method presented an inter- and intra-CV < 23.7% and parallelism had very good recovery values. The ELISA kit studied can measure bovine plasma PCT concentrations. The kit antibodies fail in binding PCT in milk samples because all centrifuged milk samples showed a lower LOD than blank samples. Only three uncentrifuged milk samples showed measurable PCT concentrations. Due to these results, the commercial ELISA kit investigated could not be employed for the detection of PCT in milk samples. [ABSTRACT FROM AUTHOR]

Abstract: Despite low per-animal productivity of ruminants in developing countries, Johne''s disease has not been investigated in buffaloes, which are primarily found in these countries. This is due to lack of expertise, diagnostic kits and priority to production diseases like Johne''s disease. Presence of pathogenic Mycobacterium avium subspecies paratuberculosis (Map) was investigated by screening of target tissues (mesenteric lymph nodes and large intestine) by culture and IS 900 PCR, in 50 sacrificed buffaloes. Indigenous ELISA kit originally developed for goats and sheep was standardized in buffaloes and used to estimate sero-presence of Map in 167 serum samples representing population of buffaloes in Agra region of North India. In culture, 48.0% buffaloes were positive from 50 tissues each from mesenteric lymph nodes (34.0%) and large intestine (36.0%). IS 900 PCR was standardized using specific primers (150 C and 921) and 229bp-amplified product was characteristic for Map. Of the 25 mesenteric lymph nodes, 40.0% were positive in IS 900 PCR. Genomic DNA from Map cultures was successfully amplified from all the 24 isolates (100.0%). Map was further genotyped as ‘Bison type’ using IS 1311 PCR–REA. Culture of tissues showed high presence of Map in target tissues, despite high culling rate in buffalos in view of high demand of buffalo meat. Specific tissue-PCR provided rapid confirmation of Map infection in sacrificed buffaloes. In tissue-PCR, all the cultures were positive as compared to 40.0% detected directly from tissues. ELISA kit using indigenous protoplasmic antigen was highly sensitive as compared to commercial antigen in detecting Map infection therefore, could be used as ‘Herd Screening Test’ in buffaloes against Johne''s disease. This pilot study first time reports a highly pathogenic ‘Bison-type’ genotype of M. avium subspecies paratuberculosis from the riverine buffaloes (Bubalus bubalis) of Agra region in North India. [Copyright &y& Elsevier]

Country lacks sensitive and indigenous diagnostic kits for the screening of goats and sheep against Johne’s disease. Therefore an indigenous ELISA kit was developed using protoplasmic antigen from native Mycobacterium avium subspecies paratuberculosis ‘Bison Type’ strain of goat origin (Kit 1). In the present study, kit 1 and two commercial kits (kit 2 and 3) were evaluated with respect to ‘Gold Standard’ fecal culture in 71 animals (55 goats and 16 sheep). Kit 1 using indigenous antigen (protoplasmic antigen) was sensitive at very low concentration (0.1 μgm / well) as compared to purified commercial protoplasmic antigen (4 μgm / well) used in kit 2, in the Type 1 reactors (strong positive as positive). Screening of 71 animals by fecal culture detected 38.0% animals (goats-40.0%, sheep-31.2%) as positive (clinical shedders of bacilli) from these farm animals. Of the farm animals located at Central Institute for Research on Goats, herds of goat were endemic whereas, sheep flocks were comparatively resistant to Johne’s disease. The 29.5 and 61.9, 15.4 and 57.7 and 4.2 and 14.0% animals (goats and sheep) were in the category of sero-reactors type 1 and 2 of the ELISA kits 1, 2 and 3, respectively. In the type 1 sero-reactors, sensitivity and specificity of kit 1, 2 and 3 was 53.7 and 86.0, 17.8 and 86.0 and 3.5 and 94.7%, respectively. Indigenous ELISA test (kit 1) was significantly superior for the screening of goatherds and sheep flocks against JD as compared to commercial ELISA kits (Kit 2 and 3). In comparison to kit 2 and 3, kit 1 had highest sensitivity, comparable specificity and substantial to nearly perfect proportional agreement (Kappa Scores) with respect to ‘Gold standard’ fecal culture in goats and sheep. Disease being endemic in herds and flocks screened using ELISA kits, Type I sero-rectors had better correlation with fecal culture in comparison to Type II sero-reactors therefore, used for estimation of sero-prevalence. Newly developed Indigenous ELISA kit was simple, inexpensive, sensitive and reliable for screening of goats and sheep population against Johne’s disease. The study reports high prevalence of Johne’s disease in farm goatherds and sheep flocks, using sensitive tests (fecal culture and ELISA kit). Results of Type 1 reaction in kit 1 were optimally correlated with culture and were good for estimating the sero-prevalence. For controlling Johne’s disease in endemic herds initial removal of the animals in strong positive category (Tyep 1 reactors), may help to remove heavy shedders. [ABSTRACT FROM AUTHOR]

Abstract: A commercially available enzyme-linked immunosorbent assay (ELISA) kit was evaluated for the determination of toxic equivalents (TEQs) of dioxin-like polychlorinated biphenyls (PCBs) in retail fish. The ELISA was highly specific for 2,3′,4,4′,5-pentachlorobiphenyl (PCB 118), which is generally the most abundant dioxin-like PCB isomer found in fish. The quantitative limit of the ELISA (using 3,3′,4′-trichloro-4-methoxybiphenyl as a surrogate standard for PCB 118) was 10ngml−1 (125pg assay−1) in the standard curve, corresponding to 50pg PCB 118g−1 in the tested sample. Good recoveries of PCB 118 (78.7–112.3%) were obtained for spiked purified fish extracts according to the ELISA. Good linearity was also obtained in dilution tests using purified fish extracts. No significant interference of the matrix was observed in the ELISA when this purification procedure was used. Recovery tests in which PCB 118 was added to fish samples also resulted in acceptable recoveries (60.2–82.3%) in the ELISA following purification. The ELISA results for fish samples correlated well with the TEQ concentrations of dioxin-like PCBs obtained by high-resolution gas chromatography/high-resolution mass spectrometry (r =0.92, n =26). These data indicate that the ELISA kit is suitable for screening retail fish for the TEQs of dioxin-like PCBs. [Copyright &y& Elsevier]

Only simple, point-of-care, assay formats of the Platellia Dengue NS1 Ag-ELISA would be suitable to identify Dengue virus in Aedes aegypti mosquitoes in dengue-endemic areas lacking sophisticated laboratory infrastructure and trained laboratory personnel. [ABSTRACT FROM AUTHOR]

A total of 328 agricultural product samples highly suspected to be contaminated, from flour companies, feed companies, and livestock farms throughout China, were surveyed for deoxynivalenol (DON) contamination using a self-assembly enzyme-linked immunosorbent assay (ELISA) kit. An ELISA kit for DON was developed with a 4.9 ng mL−1 limit of detection (LOD) in working buffer and a 200 ng g−1 LOD in authentic samples. The DON contamination detection rate was 88.7%, concentrations ranged from 200.9 to 6480.6 ng g−1, and the highest DON contamination was found in distillers' dried grains with solubles with an average of 3204.5 ng g−1. Wheat bran and wheat were found to be the most commonly contaminated samples, and the corn meal samples had the lowest average DON level. This ELISA kit is a powerful alternative method for the rapid, sensitive, specific, accurate, and high-throughput determination of DON and can meet the maximum requirement levels. This survey suggests that DON contamination in the Chinese market is serious, and the contamination risk deserves attention. Essential preventive measures should be implemented to ensure food safety and human health. [ABSTRACT FROM AUTHOR]

The recent discovery of irisin has generated considerable interest in the scientific community. However, many studies on the biochemistry and biology of this intriguing hormone yielded controversial results in humans, which were mostly attributable to a number of drawbacks in the methods used for its detection and measurement. [ABSTRACT FROM AUTHOR]

Introduction: Approximately 90% of diabetes patients often show sexual abnormalities and impotence infertility. Damages caused by hyperglycemia and oxidative conditions result in inflammatory mediators increasing such as cytokines in tissues of sex organs. The TNF-α is the first locally produced cytokines in chronic inflammation pathway. TNF-α level in diabetics blood is higher than normal people that probably histological studies of TNF-α could determine source of this increasing. Also exercise can reduce complications of diabetes especially in tissue by reducing of oxidative elements and establishing of Flypoglycemia. Materials and Methods: In this study, 40 male rats weighing 200-250 gr were used and randomly were classified into four groups; each group consist 10 rats (control, diabetic, healthy with period of 60-day exercise, diabetic with period of 60-day exercise). Treadmill exercise daily was 1 hr with 22 m/min speed. Diabetes was induced by injection intraperitoneal of streptozotocin with the amount of 60 mg/kg. After expelling of the testis under general anesthesia, samples were homogenized and TNF-α protein levels were measured according to ELISA kit (special rat TNF-α). Results: The level of TNF-α showed no significant changes among diabetic groups in testicular tissue compare to control groups. Also, exercise didn't have any negative effects on the level of TNF-α in exercise control group compare with control group. Therefore, we didn't show any significant change of TNF-α level between our groups. Conclusion: In this study, the period of disease time may be is not enough to determine the level of TNF-α via exercise treatment in testis tissues. It seems that duration of diabetic developing, severity and type of exercise could be many important reasons to change inflammatory mediators. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the efficacy of 2 commercially available soy enzyme-linked immunosorbent assays (ELISA) and use them in detecting soy proteins in selected food commodities. Both ELISA kits exhibited high sensitivity. The determined limits of detection (LOD) (approximately 2 and <1 μg/mL for Tepnel Biosystems and Elisa Systems kits, respectively) were lower than those claimed by the manufacturer. Quantification range for both kits was, however, narrower and in a lower concentration range than defined by the kit providers. Our examination revealed a positive cross-reactivity with chickpea proteins and matrix interferences for both kits. The immunoreactivity of soy proteins, when tested by the Tepnel Biosystems kit, was partially reduced by papain and bromelain hydrolysis; it was significantly decreased by protein glycation (>47%). Nondenatured and nonheated soy protein isolate (SPI) samples were also significantly less antigenic than the treated ones. [ABSTRACT FROM AUTHOR]